69-year-old vice president biggest channel is to defend that record more aggressively than president obama did. the president picked up the phone aboard air force one today to wish his veep luck on the way to campaign event many miami, where democratic senator nelson had a blunt prediction. >> tonight, joe biden will make mincemeat of paul ryan. [ applause ] >> reporter: no easy task for the vice president. even though he has more experience in debates. >> his convention speech, joe biden, portrayed a president who is engaged, up to the minute on events, who is versed in policy issues. that is not the president we saw on the debate stage in denver. >> reporter: top democrats privately say the biden game plan is to focus on the top of the ticket, hitting romney by going after the target rich ryan budget. strategy the obama camp signaled with a web video today. >> they haven't given me the math. >> well, i don't have the -- it would take me too long to go through all of the math. >> reporter: biden, though, could be on defense because unlike the first debate focused only on domestic issues t